The present invention is related generally to primary electrochemical cells and is more particularly concerned with a novel method of construction for such cells, and the cells produced by such method which results in a hermetically sealed ultra-thin compact configuration.
Primary electrochemical cells are utilized for a wide variety of applications and are commonly available in a significant assortment of sizes and shapes. Certain of these applications require that the cell be hermetically sealed to preclude the possibility of the contents escaping into the surrounding environment. Examples of such applications include space installations, where the cells are used in vacuum environments, and heart pacemakers where the environment is the human body. It may be appreciated that the reliability of these cells is extremely important and that protection against leakage of the contained electrolyte is a predominant consideration. Another application for electrochemical cells which is of continuing importance is their incorporation into electronic watches. Cells used for these purposes are required to supply low currents over extended periods of time so that hermetic sealing again is a desired feature.
The desirability for compact cell configurations in applications such as those above is readily apparent. Primary electrochemical cells having both the requisite compact configuration and the necessary discharge capacity comprise electrochemical systems having an alkaline metal anode such as lithium, a carbon or (C.sub.4 F).sub.n cathode, and an electrolyte comprising a solute dissolved in an inorganic oxyhalide or thiohalide solvent. The cathode material in such a system catalyzes the electrochemical decomposition of the solvent thereby enabling the otherwise dead weight of electrolyte solvent to be utilized as a source of electrical energy.